Display substrate motherboard and manufacturing method thereof, display substrate and display apparatus

1. A display substrate motherboard comprising: a substrate, a display substrate area on the substrate, and a mark area on a periphery of the display substrate area; wherein

the display substrate motherboard also comprises a thin film transistor disposed in the display substrate area, a mark structure disposed in the mark area and a planarization layer disposed on one side of the thin film transistor away from the substrate; and

the planarization layer comprises a groove which is disposed at the corresponding position of the mark structure and extends along a direction close to the substrate, and an orthographic projection of the groove on the substrate covers an orthographic projection of the mark structure on the substrate;

wherein the mark structure is a laminated structure, which comprises at least two of a first sub-mark disposed in the same layer as an active layer in the thin film transistor, a second sub-mark disposed in the same layer as a gate electrode in the thin film transistor, and a third sub-mark disposed in the same layer as a source/drain metal layer in the thin film transistor, which are sequentially stacked.

2. The display substrate motherboard according to claim 1 , further comprising: a reflective layer disposed on a side of the planarization layer away from the substrate; in a direction away from the substrate, a first area covering the groove in the reflective layer is lower than a second area adjacent to the first area in the reflective layer, and a step difference between the first area and the second area is larger than a preset threshold.

3. The display substrate motherboard according to claim 2 , wherein the thickness of the mark structure is 0.46 μm to 0.69 μm, and the thickness of the reflective layer is 0.8 μm to 1.2 μm.

4. The display substrate motherboard according to claim 1 , wherein

the groove penetrates through the planarization layer, and the mark structure is located in the groove; or

the groove does not penetrate through the planarization layer, and the area where the groove is located in the planarization layer covers the mark structure.

5. The display substrate motherboard according to claim 1 , wherein a center of the orthographic projection of the groove on the substrate coincides with a center of the orthographic projection of the mark structure on the substrate.

6. The display substrate motherboard according to claim 1 , wherein a cross-sectional shape of the groove is rectangular or square on a plane parallel to the substrate.

7. The display substrate motherboard according to claim 6 , wherein a distance between an edge of the orthographic projection of the groove on the substrate and an edge of the orthographic projection of the mark structure on the substrate is 20 μm to 300 μm.

8. The display substrate motherboard according to claim 1 , wherein the mark structure is disposed in the same layer as at least one of a source/drain metal layer, a gate electrode and an active layer in the thin film transistor.

9. The display substrate motherboard according to claim 1 , wherein the mark structure comprises one or more of a rectangular structure and a cross structure.

10. The display substrate motherboard according to claim 1 , wherein an area of an orthographic projection of the first sub-mark on the substrate is larger than an area of an orthographic projection of the second sub-mark on the substrate, and the area of an orthographic projection of the second sub-mark on the substrate is larger than an area of an orthographic projection of the third sub-mark on the substrate.

11. A display substrate formed by a display substrate area obtained by cutting a display substrate motherboard along a mark area, wherein

the display substrate motherboard comprises a substrate, a display substrate area on the substrate, and a mark area on a periphery of the display substrate area;

the display substrate motherboard also comprises a thin film transistor disposed in the display substrate area, a mark structure disposed in the mark area and a planarization layer disposed on one side of the thin film transistor away from the substrate; and

the planarization layer comprises a groove which is disposed at the corresponding position of the mark structure and extends along a direction close to the substrate, and an orthographic projection of the groove on the substrate covers an orthographic projection of the mark structure on the substrate;

wherein the mark structure is a laminated structure, which comprises at least two of a first sub-mark disposed in the same layer as an active layer in the thin film transistor, a second sub-mark disposed in the same layer as a gate electrode in the thin film transistor, and a third sub-mark disposed in the same layer as a source/drain metal layer in the thin film transistor, which are sequentially stacked.

12. The display substrate according to claim 11 , wherein the display substrate motherboard further comprises a reflective layer disposed on a side of the planarization layer away from the substrate; in a direction away from the substrate, a first area covering the groove in the reflective layer is lower than a second area adjacent to the first area in the reflective layer, and a step difference between the first area and the second area is larger than a preset threshold.

13. The display substrate of claim 11 , wherein

the groove penetrates through the planarization layer, and the mark structure is located in the groove; or,

the groove does not penetrate through the planarization layer, and the area where the groove is located in the planarization layer covers the mark structure.

14. The display substrate of claim 11 , wherein a center of the orthographic projection of the groove on the substrate coincides with a center of the orthographic projection of the mark structure on the substrate.

15. The display substrate of claim 11 , wherein a cross-sectional shape of the groove is rectangular or square on a plane parallel to the substrate.

16. The display substrate of claim 11 , wherein the mark structure is disposed in the same layer as at least one of a source/drain metal layer, a gate electrode and an active layer in the thin film transistor.

17. A display apparatus comprising the display substrate according to claim 11 .

18. A manufacturing method of a display substrate motherboard, wherein the display substrate motherboard comprises a substrate, a display substrate area on the substrate, and a mark area on a periphery of the display substrate area;

the manufacturing method comprises:

forming a thin film transistor in the display substrate area, and forming a mark structure in the mark area;

forming a planarization layer covering the thin film transistor and the mark area; wherein the planarization layer is disposed on one side of the thin film transistor away from the substrate and

forming a groove which is disposed at the corresponding position of the mark structure and extends along a direction close to the substrate in the planarization layer; wherein the planarization layer comprises the groove, and an orthographic projection of the groove on the substrate covers an orthographic projection of the mark structure on the substrate;

wherein the mark structure is a laminated structure, which comprises at least two of a first sub-mark disposed in the same layer as an active layer in the thin film transistor, a second sub-mark disposed in the same layer as a gate electrode in the thin film transistor, and a third sub-mark disposed in the same layer as a source/drain metal layer in the thin film transistor, which are sequentially stacked.